Slag breaker shield for degassing apparatus

ABSTRACT

This invention is a shield and slag breaker device for application to the nozzles of degassing apparatus which shields the nozzle ends until penetration is made through the slag crust. It comprises a unitary member of sheet metal material having a shallow cone body, a base of which extends radially outwardly to form an annular ring. The peripheral edge of the annular ring is upturned and means are provided on the upturned edge for supporting the device of this invention so that the annular ring abuts against the annular end of the nozzle of the degassing vessel.

United States Patent 36 W I] Do 66 66 22 m m .1. N w m wm mm D. HKS 73 66 999 111 ll, [41 1 5 7 1 8 Primary Examiner-Gerald A. Dost Attorney -Walter Leuca [2]] App]. No. 7,184 [22] Filed Jan. 30, 1970 [45] Patented July 13, 1971 G W G E n m w m H s m m m mm as w ABSTRACT: This invention is a shield and slag breaker device for application to the nozzles of degassing apparatus which shields the nozzle ends until penetration is made through the slag crust. It comprises a unitary member of sheet metal material having a shallow cone body, a base of which extends radially outwardly to form an annular ring. The peripheral edge of the annular ring is upturned and means are provided on the upturned edge for supporting the device of this invention so that the annular ring abuts against the annular end of the nozzle of the degassing vessel.

n muo a 4HWW G m mk' flm m 6 w m Mr 2 "HI Mm n m n e m mm D w n E H m mm Jm Um m r. u m an CS M 4 6U M .m 1 1] l w m mm m w PATENIEU JUL 1 3 l9?! INVENTOR Horace FREEMAN A 'I'IORNI Y SLAB BREAKER SE-IllIlElLlD FOR DIEGASSIIN G APPARATUS BACKGROUND OF INVENTION This invention is applicable to apparatus used for degassing molten metal. In particular, it relates to an improved article of manufacture for shielding the tubular extensions of a degassing vessel while breaking through the slag or crust of the molten metal such as steel or the like.

In steel mill degassing operation, conventional degassing equipment includes a vacuum vessel having one or more tubular extensions, commonly referred to as nozzles or snorkels, one of which may be provided with an inlet for injecting therein an inert gas. The vacuum vessel is lowered so that the ends of the tubular extensions penetrate the slag crust formed on the molten metal in the ladle to a submerged depth in the liquid metal such as steel in the ladle. The degassing operation is then initiated. The process is well known to those skilled in the art to which this invention pertains. The problem that this invention is directed to is the problem of penetrating the slag crust formed on the surface of the molten steel in the ladle since it is essential that the submerged ends of the tubular extensions be free from large pieces of slag to provide an unobstructed circulatory path therebetween since the entrance of slag into the vacuum vessel is hazardous and detremental to the degassing process.

In the prior art practice, a sheet metal blank is sectorially cut and the two separated radial edges are brought together and tack welded to form a cone which is brought to bear against the open end of each tubular extension and drawn up thereagainst by means of support wires. The base end of the fabricated cone is diametrally extensiveof the outer diameter of the tubular extension and is internally provided with a circular sheet metal piece tack welded around the circumference thereof to the interior wall of the cone which serves as a seating surface for the open end of the tubular extension and reinforces the fabricated cone structure.

The principal disadvantage of the prior art cone slag breaker which can be adequately described as an ordinary cone-shaped body internally reinforced as described above, is the fact that as fabricated articles they are heavy in weight and costly to manufacture since the cone structure must be sufficiently peaked or pointed and internally reinforced with an added sheet to provide the strength to break the slag crust covering the molten metal in the ladle and consequently the cone-forming sheet must be sufficiently expansive from which a long or peaked cone may be obtained, and since each cone breaker is expended as soon as the cone breaker penetrates the crust and enters the molten metal and thereby immediately melted, any excess in forming material usage is multiplied a thousand fold. Another disadvantage is that the excess weight thereof requires more than one workman to lift and support each cone as it is connected to the nozzle.

SUMMARY OF INVENTION In order for the tubular extensions of the vacuum vessel to penetrate the slag crust of the ladle without pieces thereof entering therein, I have invented an improved slag breaker shield to cap the open end of each tubular extension.

The structure of my invention is novel since it is essential that it be constructed of thin material such as sheet metal so that it be sufficiently light in weight to be handled by one workman and may easily and rapidly melt as soon as it is submerged into the molten steel, that it possess inordinate strength to withstand the slag-breaking impact by the nozzle of the vacuum vessel, and that the cone body be short in height so that a minimum of forming material be used in the manufacture thereof since the slagbreaking shield of my invention is expended on a single use.

Accordingly, a principal object of my invention is to provide a slag breaker shield which utilizes the minimum forming material, is light in weight, easy to handle, has great strength, and is economical to manufacture.

Another object of my invention is to provide slag breaker shield having a unitary structure.

Still another object of my invention is to provide a slag breaker shield which will not rupture upon impact.

Other objects and advantages of my invention will become more apparent after a careful study of the following detailed description having reference to the accompanying drawing which illustrates a preferred embodiment thereof.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan elevation ofthe slag breaker shield of my invention;

FIG. 2 is a cross-sectional view of a slag breaker shield of my invention shown in operative relation with the annular end of a tubular extension depending from a vacuum vessel which is shown in dotted lines;

FIG. 3 is a diagrammatic view of the vacuum degassing apparatus illustrating the relative positions of the component parts thereof to which my slag breaker shield is connected;

FIG. 4i is a line diagram of the slag breaker shield of my invention; and

FIG. 5 shows force vector diagrams illustrating the action of forces at selected points of the line diagram of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the slag breaker shield of my invention is designated generally by the numeral 10. It comprises a unitary member having a conical body 12 in the form of a shell and an annular ring 14 circumscribing the base of the cone body. The base of cone body 12 is approximately diametrally coextensive with the internal diameter of the annular end of tubular extension 20 to which shield 10 is abutted. The outer perimeter of annular ring I4 is circumferentially extensive of the external diameter of tubular exter; sion 20 and is upturned as at B6 to serve the multiple function of stiffening the annular ring in its planular direction and provide an annular trough in which is laid an asbestos seal rope (not shown) between the tubular extension 20 of vacuum vessel 22 and the upturned rim 16 when the slag breaker shield 10 of my invention is abuttingly connected to the end of tubular extension 20. Holes 24 are provided in upturned rim 16 circumferentiallyspaced therearound through which the ends of support wires 26 are tied or twisted for holding a sag breaker shield 10 of my invention to each tubular extension 20 of vacuum vessel 22.

In the operation of my invention, each tubular extension or nozzle 20 of vacuum vessel 22 of the degassing apparatus is capped or shielded by abutment thereto of annular ring 14 of slag breaker shield 16), and supported thereagainst by a plurality of wires 26 tied to the upturned rim 16 through holes 24 spaced therearound. The other ends of wires 26 are drawn up tight on hook means or other like anchor means on tubular extensions 20.

The slag breaker shield 10 of my invention is manufactured with considerable savings by forming it from a unitary metal sheet circular in shape. It is shaped into the component parts above described by spin forming on a mandrel having said form. Throughout the manufacture of my invention the unitary integrity of the forming material is maintained and a lowangled or short cone may be formed having sufficient impact strength to withstand collapse or rupture during penetration of the crust. The annular ring portion 14 of my invention serves to seat the annular end of nozzle 20 of vacuum vessel 22 from which arrangement added rigidity is obtained, and also provides through its width, compressive stock material for absorbing the horizontal component of the impact force which is transmitted through the cone wall. Annular ring 14 formed integral with cone 12 radially extending outward therefrom provides a compressive stock of material completely therearound allowing a greater horizontal force to be absorbed thereby and accordingly, the length or height of cone 12 can be reduced considerably resulting in great saving of forming material. The upturned edge 16 also serves a double function in providing an annular well to seat an asbestos seal rope when the tubular end of nozzle 20 of vacuum vessel 22 is pressed against annular ring 14, and the function of providing lateral rigidity to annular ring 14 to avoid buckling under the compressive force of the horizontal component of the impact force on cone body 12.

FIGS. 4 and 5 illustrate the action of the forces on the slag breaker shield of my invention and demonstrate why my invention can be constructed of less forming material and is inherently stronger than the simple cones of the prior art. In FIG. 4, point A is the apex of the cone body 12, and points B and C are any points at the juncture of the base of cone body 12 and annular ring M.

In FIG. 5, points A, B, and C are shown in the abstract with the force vectors acting thereat when impact is made against the crust of the slag assuming that the forces are in equilibrium, the vertical force of impact Fi on the apex A of cone body 12 is equal and opposite to the vertical components of the reactionary force P0 of the cone body 12. Forces Fc acting through cone body 12 at any point B and C at the junction of cone base 12 and annular ring 114, are resolved into vertical and horizontal component forces which are equal and opposite to forces Nf exerted by nozzle and forces Cf which represents the compressive strength of the material of annular ring 14. The compressive strength of the material of annularring 14 through the width of the annular ring )14 is considerable since the planular direction thereof is maintained by the upturned edge 16 and the seating thereon of the annular end of nozzle 20. Therefore, to utilize the minimum of forming material, and also provide a penetrating cone of sufficient strength to break the slag crust 28, the height requirement of the cone body 12 is reduced considerably. As the height of cone 12 is reduced, the horizontal components of forces Fc are increased, and because ring 114 is integral therewith and extends radially outward from the base of cone body 12, the compressive strength of the material thereof represented by force vectors Cf is available in sufficient magnitude to counteract the horizontal component of any force Fe encountered in actual use and thereby keep any point B and C in equilibrium, that is, prevent rupture or collapse of the slag breaker shield upon impact.

I claim:

1. A slag breaker shield for degassing nozzle comprising:

a cone-shaped body; and

an annular ring circumscribing said cone-shaped body at the base thereof, the distal circumferential edge of said annular ring being upturned to provide a rim therearound.

2. The slag breaker shield of claim 1 wherein said cone body and annular ring are unitary in forming material.

3. A slag breaker shield for degassing nozzle comprising:

a cone-shaped shell;

an annular ring circumscribing said cone-shaped shell at the base thereof; and

a rim circumferentially around said annular-shaped ring,

4. The slag breaker shield of claim 3 wherein said coneshaped shell, annular-shaped ring and rim are further characterized as being unitary in forming material.

5. A slag breaker apparatus comprising:

a reusable tubular nozzle having an annular end; and

an expendable unitary sheet metal member supported against said annular end of said tubular nozzle,

said expendable unitary sheet metal member having a conical-shaped body projecting from the center of said tubular nozzle end, and annular ring circumscribing the base of said conical body concentrically seated against said annular end of said tubular nozzle, and expendable means connecting the distal circumferential edge of said annular ring and said tubular nozzle for supporting said sheet metal member against said end of said tubular nozzle.

6. The slag breaker apparatus of claim 5 wherein said annular ring is further characterized by a rim circumferentially therearound circumscribing said end of said tubular nozzle.

mirth STATES PATENT @FHQE @ER'HHQATE @E QEUMN Patent No. 3 592 456 Dated July 13 1971 Lonis P. Miklos PAGE 1 Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Cancel the present sheet of drawing and insert sheet 1, containing figures 1 to 5.

FORM P0-1050 (10-69) USCOMM-DC scam-ps9 U 5, GOVERNMENT PRINTING OFFICE: 959 O-356-334 Warm sums PATENT oFwcE CERTEHCATE 0F CREGHQ Patent No. 3 592 456 Dated y 13 1971 lnventofls) Louis F. Miklos PAGE It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

FORM PO-1050 (10-69) USCOMM-DC 60376-P69 us GOVERNMENT PRINTING OFFICE: I989 0-366-334 UNKTED STATES PATENT mm QERHWCATE Di CQEQTEN Patent No. 92, 4:56 Dated July 13, 1971 Inventor(s) Louis F. Miklos PAGE 3 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the caption, that portion of the inventor's address reading 6151 Delaware St. Lake County, Ind. 46409" should read 6151 Delaware St. Gary, Ind. 46409".

Signed and sealed this 4th day of January 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents FORM PO-105O (10-69) USCOMM-DC 60376-P69 U.5. GOVERNMENT PRINTING OFFICE: I969 0-365-334 

2. The slag breaker shield of claim 1 wherein said cone body and annular ring are unitary in forming material.
 3. A slag breaker shield for degassing nozzle comprising: a cone-shaped shell; an annulaR ring circumscribing said cone-shaped shell at the base thereof; and a rim circumferentially around said annular-shaped ring.
 4. The slag breaker shield of claim 3 wherein said cone-shaped shell, annular-shaped ring and rim are further characterized as being unitary in forming material.
 5. A slag breaker apparatus comprising: a reusable tubular nozzle having an annular end; and an expendable unitary sheet metal member supported against said annular end of said tubular nozzle, said expendable unitary sheet metal member having a conical-shaped body projecting from the center of said tubular nozzle end, and annular ring circumscribing the base of said conical body concentrically seated against said annular end of said tubular nozzle, and expendable means connecting the distal circumferential edge of said annular ring and said tubular nozzle for supporting said sheet metal member against said end of said tubular nozzle.
 6. The slag breaker apparatus of claim 5 wherein said annular ring is further characterized by a rim circumferentially therearound circumscribing said end of said tubular nozzle. 